Background Romiplostim is a new second-generation thrombopoietic agent that stimulates thrombopoietin receptors and platelet production. Purpose To evaluate the efficacy and safety of romiplostim in a splenectomised man with idiopathic thrombocytopenic purpura (ITP) who had not responded to other treatments. Materials and methods Follow-up over 2 years of treatment with romiplostim in a 64-year-old patient diagnosed with ITP in 2005. Previously high doses of steroids and non-specific intravenous immunoglobulins (IVIG) had been tried with a bad response; the patient was splenectomised in 2007. In spite of treatment with IVIG 2 g/kg and rituximab 375 mg/m2/week the platelet count did not rise. In September 2009 he started romiplostim 1 mcg/kg/week (dose=75 mcg), increasing gradually as indicated in the SPC. The authors evaluated the efficacy through the platelet count (noted in the clinical history), aim: 50–200 109/litre without bleeds. The adverse effects evaluated the safety. Results Splenectomy, treatment with IVIG and rituximab increased the platelet count in a short time to over 50×109/litre; but this count reduced drastically. After the first dose of romiplostim the platelet count rose from 12 to 99×109/litre. The right platelet count was achieved with a dose of 3 mcg/kg (225 mcg) reduced to 150 mcg when the count was over 200×109/litre. During this period the dose was: 19 weeks of 225 mcg, 30 weeks of 150 mcg and 4 weeks of 75 mcg, aligned with the blood test results. During the 2-year follow-up the average platelet count has been 147×109/litre (between 30 and 323×109/litre). There were no episodes of bleeding (hematomas or epistaxis). The only adverse effect has been colds when the dose was administered. Conclusions Romiplostim has proved as an effective option for maintaining the platelet count in this splenectomised patient with ITP who was resistant to other treatments. Romiplostim is well tolerated with no need to reduce the dose because of adverse effects. Although this drug does not cure the disease it improves the quality of life of the patients without causing bleeds.